Electric light bulb and method for manufacturing same



J. A. HEANY Nov. 24, '1931.

ELECTRIC LIGHT BULB AND METHOD FOR MANUFACTURING SAME Filed Sept. 8 1925 2 Sheets-Sheet- INVENTOR Jhw Ana/v HEANY ATTORNEY Nov. 24, 1931. J. A. HEANY 1,833,487

ELECTRIC LIGHT BULB AND METHOD FOR MANUFACTURING SAME Filed Spt. 8, 1926 2 Shets-Sheet 2 a fl. 57 37 5 55 if 1: ,1 2f

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Ill-Iii 26 llllllllliflHlflllllllfllllllllllllh J4 INVENTOR Jaw/v A445 fiEA/VY ATTORNEY Patented Nov. 24, .1931

UNITED STATES PATENT OFFICE JOHN ALLEN HEANY, OF NEW HAVEN, CONNECTICUT, ASSIGNOB TO SIRIAN' LAMP OOH- rm, OF NEW HAVEN, CONNECTICUT, A. CORPORATION 01' DELAWARE ELECTRIC LIGHT BULB AND METHOD FOR MANUFACTURING SAME Application fled'september 8, 1926. Serial 110. 184,218.

This invention relates to the manufacture of tipless electric light bulbs and particularly to the manufacture of stems for such bulbs through which the air must be exhausted from the bulb, and by means of which the lead in wires are connected to the lighting filament in the bulb.

In the manufacture of tipless electric light bulbs, it is necessary to exhaust the air through the stem of the-bulb and to accomlish this, an exhaust tube is provided which 1s fused to the stem. Great 'difliculty has been experienced in fusing the exhaust tube to the stem, and at the same time maintaining the opening throu h the tube. To keep the opening through t e exhaust tube open, air is sometimes directed through thetube during.

the fusing process or the tube is sometimes filled with a substance which will crumble in the action of heat so that it may be shaken or washed from the tube after the fusing process is completed. I

One of the objects of. this invention .is to provide a method of manufacturing tipless electric light bulbs which will maintain the opening through the exhaust tube during the fusing process in a simple and less expensive manner than .has been heretofore used. Another object of the invention is to provide an exhaust tube for a stem for a tipless electric light bulb which has been reinforced against a collapse during the fusing process. An-

other object of the invention is to provide a the parts are arranged "*before the fusing,

process Fig. 2. is a front elevation of the stem after the fusing process;

Figs. 3 and 4 are pers ective views of two embodiments of the rein orcing member;

Fig. 5 is a front elevation of a stem adapted {)be used in a different form of electric light Fig. 6 is a side view of the stem shown in Fig.

Fig. 7 is a side elevation of a machine in which the stem.may be made, parts being broken away for purpose of illustration;

Fig. 8 isa front view of the machine shown in Fig. 7

Fig. 9 is an enlarged sectional elevation of a portion of the machine showing the tubes held therein; and

. Fig. 10 is a plan view of the clamps for holding the tubes in position.

Referring now more specifically to the drawings, my improved stem comprises a stem tube '10 into which is inserted an exhaust tube 11 and lead in wires 12. Areinforcing member 13 comprising a sleeveihaving a slot 14 extending from end to end on one side thereof is inserted in the tube 11 and may be held in the desired position therein by a slight indentation 15 formed in the side of the exhaust tubell, or if desired, may be held in position by'another method to be hereinafter described. The reinforcing member may be made of any material which is non-fusible at the fusing temperature of glass or it may also be formed of a coil of wire 16, Fig. 4.

The stem tube 10, exhaust tube 11 and wires 12 may be supported in position shown in Fig. 1, the tubes heated and the sides of the lower end of the stem tube pressed in fusing the two tubes together and forming a flat mass of glass 17 which cloms' the end of the stem tube and seals the lead in wires therein. The reinforcing member 13 prevents the glass of the exhaust tube 11 from collapsing when it is heated to the fusing temperature and when the sides of the stem tube are pressed against it. v

The stem as shown in Figs. 1 and 2 is adapted to be 'usedin large electric light bulbs, the end 18 of the exhaust tube forming a support for the lighting element'or filament 18a of the bulb. After the stem has been completed, as shown in Fig. 2, the filament is added and the stem and filament inserted in a bulb 19 having a rounded tipless end, and the bulb and stem fused together at 20 in -a manner well known to the art.

The-stem shown in Figs. 5 and 6 is adapted to be used in small electric light bulbs which do not need a support for the fighting filament. In this case the exhausttube 11 is out ofi at 21 adjacent the end of the reinforcing member and serves only to provide an opening into the interior bulb through whic the air may be exhausted.

The method of manufacturing this improved stem is best carried out by the use of the machine shown in Figs. 7 to 10. A plur rality of these machines are mounted on a spider, one arm 22 of which is shown in Fig. 1. The end of the arm 22 has a sleeve-23 rotatably mounted therein uponthe lower end of which is mounted a gear '24 and to the upper end of which is attached the standard 25 by means of the set screw 26. The gear wheel 24 meshes with the gear 27 which is driven b a motor (not shown) which causes the s eeve 23 and the standard 25 to rotate about the axis of the sleeve, 23. A

pair of rods 28 are rotatably mounted in lugs 29 and 29a formed integral with the standrod, and which are adapted to support thestem tube 10 between the ends thereof, notches similar to those in the arms 30 being 1 providedto fit around the sides of the stem tube. Arms 34 are provided at the bottom of the rods 28, one arm being attached to each rod and a spring 35 is disposed between the arms 34 to urge them apart. The. arms 34 g may have rounded ends36 to facilitate the grasping between thefingerS,-and when'the arms are so grasped and squeezed together, the clam arms 30 and 33 are caused to open so that t etubes 10 ,and 11 may be or removed therefrom. a

. Amp 37 is adjustably supported from thestandard 25 by means of a post 38 and a set screw 39. The cup 37 has an openin in the bottom thereof through whicli'fiie exhaust tube 11 is adapted to fit, the bottom of the c u being larger than the opening 40 to prom e a shelf upon'which the leadin wires 12 are adapted to be rested before the tubes 10 and 11 are fused together.

adapted to be reciprocated therein of a lever 42 which is pivoted at,

sleeve 23 by means of a key Mgiand is A sleeve 41 is slidably mounted within the means to an arm 44 integral with the arm 22 of the spider and the other end of which is bifurcated and engages a s 001 45 attached to the lower end of the s eeve 41. A pair of arms 57 having fingers 570. are ivoted to the standard 25 by screws 58 an are pivotally connected to the upper end of the sleeve-41 by screws 60. When the-sleeve 41 is raised by means of the lever 42, the fin ers 57a on the arms 57 are brought toget er against the stem tube 10, the stem tube against the exhaust tu A shaft 46 is dis sed within the sleeve 41 and is held rigi ly with relation to the standard 25 by a clamp 47 integral with the standard 25. The shaft 46 may be raised or ressing lowered in the clamp 47 and held in adjusted position by the set screw 48. A cu 49 is threaded on to the upper endofthe s aft 46 and is ada' ted to be held firmly thereon by means of t e thumb screw 50. This cup is adapted to receive and support the lower end of the exhaust tube 11. If desired a wire 51 may be slidably mounted in'a hole 52 in the shaft 46 passing uvwardlythrou h a hole 53 in the cup 49 and up through t e tube 11 for the reinforcing mem r 13 therein. The hole 53 in the shaft 46 opens out into a slot 54 and the lower end of the wire 51 is bent outwardly to form a handle 55 by which the wire may be raised and lowered to any desired position with relation to the tube 11. The wire may be held in its adjusted position b means of a thumb'screw 56 in the side 0 the shaft 46. l s

In the operation of the machine, a flame is directed against the tubes by the burner 61. the tubes, together with the standard being rotated at the same time by the ear 27. When the. tubes have been heate to a fusible temperature, the lever 42 may be depressed which brings the arms 57 and fingers 57a to ether and fuses the stem tube 10 against t e exhaust tube 11 and seals the wires therebetween, forming the flat mass urpose of supporting the of glass 17. The machineis then stopped [and the tubes released by pressing the arms ,34 whereupon the finished stems may be removed from the machine. If the indentations 15 are provided in the exhaust-tube 11 as shown m Fig. 1, it is not necessary to use the rod' 51, such indentations acting to support the reinforcing member.

' It will be evident from the above description that I have provided an inexpensive and simple method of maintainin the opening through the exhaust tube 0 a ti less electric light bulb without\the use 0 expsnsive air blastsor other well known methadapt come a p of the finished bulb. v V

Many modifications of the stem shojvn in the drawings, may be resorted to without 1:13 simple reinforcing member being. to main in the stem and tobe departing from the spirit of the invention, and I do not therefore desire to limit myself to the embodiments shown, but to interpret the invention broadly within the scope of the appended claims:

Havlng described my invention what I claim and desire to secure by Letters Patent is:

1. The method of making a tipless electric lamp which comprises providing an element supporting glass tube through which the lamp is adapted to be exhausted; forming a slight indentation in said tube; inserting a hollow reinforcing member into said tube to rest upon said indentation; inserting said tube to ether with lead in wires into a larger glo e supporting glass tube; and simultaneously fusing said tubes together adjacent said reinforcing member and sealing said lead in wires therebetween.

2. A stem for tipless electric bulbs comprising a stem tube closed at one end; an exhaust tube spaced within said stem tube extending beyond each end thereof and integral with and supported by the closed end of said stem tube; and a resilient reinforcing member within said exhaust tube adjacent the closed end of said stem tube to maintain at all times an opening through said exhaust tube, said resilient member being in the form of a tube with an axial slot extending from end to end thereof.

3. A stem for tipless electric bulbs comprising a stem tube closed at one end; an exhaust tube extending through said stem tube beyond the ends thereof and integral with and supported by said closed end thereof; and a reinforcing sleeve having a slot extending from end to end along one side thereof within said exhaust tube at the oint .where said exhaust tube passes throug the closed end of said stem tube.

4. A stem for tipless electric bulbs comprising a stem tube closed at one end; an exhaust tube placed within a stem tube and extending beyond each end thereof and integral therewith at said closed end; a reinforcing member of non-fusible material within said exhaust tube at the point of fusion with the said stem tube, whereby a permanent opening through the exhaust tube is maintained; and positive means within the exhaust tube for preventing axial movement of the reinforcing member in one direction.

In testimony whereof, I afiix my signature.

JOHN ALLEN HEANY. 

